The present invention relates to heaters of the type in which a combustible substance is burnt to release heat. More particularly the invention relates to radiant heaters for heating industrial buildings such as factories, warehouses, hangers and other large structures.
It is known to heat large buildings, and in particular large industrial premises by means of radiant heaters, and typical radiant heaters used for this purpose consist of a U-tube radiator system, a burner such as a gas burner being connected to one end of the tube and a fan being arranged at the other end of the tube for extracting combustion gases from the tube. The U-tube is suspended below a heat reflective housing, which reflects radiation emitted from the tube towards the ground. Such a heater is disclosed in, for example, British Patent Application GB 2145218.
A major problem encountered with such radiant heaters lies in ensuring that the radiant flux density at ground level is as uniform as possible, and that hot spots and cold spots are avoided. This represents a problem because whilst a particular form of radiant heater may be configured to provide optimal heating in a building of one size and shape, it may provide a far from ideal heating effect when used in a building of a different size and shape. In particular, it has proved difficult to compensate for variations in the mounting height above ground level, the mounting height generally being dependent upon the availability of support structures such as roof support structures on which to mount the heaters.